Surgical stapler knife motion controls

ABSTRACT

A surgical instrument includes an end effector, a firing member movable distally to effect a firing motion at the end effector, wherein the firing member comprises a cam slot, and a lockout pawl. The lockout pawl has a cam feature receivable in the cam slot, wherein the cam slot is configured to guide the cam feature to cause a rotation of the lockout pawl between a first position where the lockout pawl permits the distal movement of the firing member, and a second position where the lockout pawl prevents the distal movement of the firing member.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation application claiming priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 15/797,200,entitled SURGICAL STAPLER KNIFE MOTION CONTROLS, filed Oct. 30, 2017,now U.S. Patent Application Publication No. 2019/0125343, the entiredisclosure of which is hereby incorporated by reference herein.

BACKGROUND

The present invention relates to surgical instruments and, in variousarrangements, to surgical stapling and cutting instruments and staplecartridges for use therewith that are designed to staple and cut tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the embodiments described herein, together withadvantages thereof, may be understood in accordance with the followingdescription taken in conjunction with the accompanying drawings asfollows:

FIG. 1 illustrates perspective view of a surgical instrument inaccordance with at least one aspect of the present disclosure;

FIG. 2 illustrates is a partial perspective view of an interchangeableshaft assembly and a perspective view of a handle of the surgicalinstrument of FIG. 1 in an unassembled configuration;

FIG. 3 illustrates a perspective view of an end effector of the surgicalinstrument of FIG. 1;

FIG. 4 illustrates a partial perspective view of the surgical instrumentof FIG. 1;

FIG. 5 illustrates perspective views of a sled, a firing member, and alockout pawl of the surgical instrument of FIG. 1;

FIGS. 6-8 are partial cross-sectional views of the surgical instrumentof FIG. 1 illustrating advancement of a firing member from a homeposition in the absence of an unfired staple cartridge;

FIGS. 9-11 are partial cross-sectional views of the surgical instrumentof FIG. 1 illustrating advancement of a firing member from a homeposition in the presence of an unfired staple cartridge;

FIGS. 12-14 are partial cross-sectional views of the surgical instrumentof FIG. 1 illustrating the return of a firing member to a home position;

FIG. 15 illustrate four consecutive positions of a firing member of thesurgical instrument of FIG. 1 relative to a lockout pawl; and

FIG. 16 is a logic diagram of a control circuit of the surgicalinstrument of FIG. 1.

DETAILED DESCRIPTION

Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. Well-known operations, components, andelements have not been described in detail so as not to obscure theembodiments described in the specification. The reader will understandthat the embodiments described and illustrated herein are non-limitingexamples, and thus it can be appreciated that the specific structuraland functional details disclosed herein may be representative andillustrative. Variations and changes thereto may be made withoutdeparting from the scope of the claims.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), “include” (and any form of include, such as “includes” and“including”) and “contain” (and any form of contain, such as “contains”and “containing”) are open-ended linking verbs. As a result, a surgicalsystem, device, or apparatus that “comprises,” “has,” “includes” or“contains” one or more elements possesses those one or more elements,but is not limited to possessing only those one or more elements.Likewise, an element of a system, device, or apparatus that “comprises,”“has,” “includes” or “contains” one or more features possesses those oneor more features, but is not limited to possessing only those one ormore features.

The terms “proximal” and “distal” are used herein with reference to aclinician manipulating the handle portion of the surgical instrument.The term “proximal” refers to the portion closest to the clinician andthe term “distal” refers to the portion located away from the clinician.It will be further appreciated that, for convenience and clarity,spatial terms such as “vertical”, “horizontal”, “up”, and “down” may beused herein with respect to the drawings. However, surgical instrumentsare used in many orientations and positions, and these terms are notintended to be limiting and/or absolute.

Various exemplary devices and methods are provided for performinglaparoscopic and minimally invasive surgical procedures. However, thereader will readily appreciate that the various methods and devicesdisclosed herein can be used in numerous surgical procedures andapplications including, for example, in connection with open surgicalprocedures. As the present Detailed Description proceeds, the readerwill further appreciate that the various instruments disclosed hereincan be inserted into a body in any way, such as through a naturalorifice, through an incision or puncture hole formed in tissue, etc. Theworking portions or end effector portions of the instruments can beinserted directly into a patient's body or can be inserted through anaccess device that has a working channel through which the end effectorand elongate shaft of a surgical instrument can be advanced.

Although various aspects of the present disclosure have been describedherein in connection with linear staplers, these aspects can besimilarly implemented in other surgical staplers such as, for example,circular staplers and/or curved staplers. Also although various aspectsof the present disclosure are described in connection with a hand-heldinstrument, these aspects can be similarly implemented in roboticsurgical systems. Various suitable robotic surgical systems aredisclosed in U.S. Patent Application Publication No. 2012/0298719,entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENTARRANGEMENTS, filed May 27, 2011, now U.S. Pat. No. 9,072,535, theentire disclosure of which is incorporated by reference herein.

Referring primarily to FIGS. 1-3, a surgical instrument 10 comprises ashaft 11 and an end effector 12 extending from the shaft 11. The endeffector 12 comprises a first jaw 14 and a second jaw 15. The first jaw14 comprises a staple cartridge 16. The staple cartridge 16 isinsertable into and removable from a cartridge pan or channel 17 of thefirst jaw 14; however, other embodiments are envisioned in which thestaple cartridge 16 is not removable from, or at least readilyreplaceable from, the first jaw 14. The second jaw 15 comprises an anvil18 configured to deform staples ejected from the staple cartridge 16.The second jaw 15 is pivotable relative to the first jaw 14 about aclosure axis; however, other embodiments are envisioned in which thefirst jaw 14 is pivotable relative to the second jaw 15. The surgicalinstrument 10 further comprises an articulation joint 20 configured topermit the end effector 12 to be rotated, or articulated, relative tothe shaft 11. The end effector 12 is rotatable about an articulationaxis extending through the articulation joint 20. Other embodiments areenvisioned which do not include an articulation joint.

Referring to FIG. 2, in various examples, the surgical instrument 10includes a housing 19 that comprises a handle assembly 29 that isconfigured to be grasped, manipulated, and actuated by the clinician.The housing 19 is configured for operable attachment to aninterchangeable shaft assembly 36, which includes the end effector 12and at least a portion of the shaft 11. In accordance with the presentdisclosure, various forms of interchangeable shaft assemblies may beeffectively employed in connection with robotically controlled surgicalsystems as well hand-held instruments. The term “housing” may encompassa housing or similar portion of a robotic system that houses orotherwise operably supports at least one drive system configured togenerate and apply at least one control motion that could be used toactuate interchangeable shaft assemblies. The term “frame” may refer toa portion of a hand-held surgical instrument. The term “frame” also mayrepresent a portion of a robotically controlled surgical instrumentand/or a portion of the robotic system that may be used to operablycontrol a surgical instrument. Interchangeable shaft assemblies may beemployed with various robotic systems, instruments, components, andmethods disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLINGINSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which isherein incorporated by reference in its entirety.

Referring primarily to FIGS. 3 and 4, the staple cartridge 16 comprisesa cartridge body 21. The cartridge body 21 includes a proximal end 22, adistal end 23, and a deck 24 extending between the proximal end 22 andthe distal end 23. In use, the staple cartridge 16 is positioned on afirst side of the tissue to be stapled and the anvil 18 is positioned ona second side of the tissue. The anvil 18 is moved toward the staplecartridge 16 to compress and clamp the tissue against the deck 24.Thereafter, staples (not shown) removably stored in the cartridge body21 can be deployed into the tissue. The cartridge body 21 includesstaple cavities 26 defined therein, wherein staples are removably storedin the staple cavities 26. The staple cavities 26 are generally arrangedin six longitudinal rows. Three rows of the staple cavities 26 arepositioned on a first side of a longitudinal slot 27 and three rows ofthe staple cavities 26 are positioned on a second side of thelongitudinal slot 27. Other arrangements of the staple cavities 26 andstaples may be possible.

As described in greater detail below, the surgical instrument 10 staplesand cuts tissue by employing a firing mechanism carefully orchestratedto perform the tissue stapling ahead of the tissue cutting. To ensureavoidance of an instance where the tissue cutting occurs ahead of, orwithout, tissue stapling, the surgical instrument 10 is equipped withvarious safety features.

The staples of the staple cartridge 16 are generally supported by stapledrivers (not shown) in the cartridge body 21. The drivers are movablebetween a first, or unfired position, and a second, or fired, positionto eject the staples from the staple cavities 26. The drivers areretained in the cartridge body 21 by a pan or retainer which extendsaround the bottom of the cartridge body 21 and includes resilientmembers configured to grip the cartridge body 21 and hold the retainerto the cartridge body 21. The drivers are movable between their unfiredpositions and their fired positions by a sled 32 (FIG. 4). The sled 32is movable between a proximal position adjacent the proximal end 22 anda distal position adjacent the distal end 23. The sled 32 comprises aplurality of ramped surfaces 33 configured to slide under the driversand lift the drivers, and the staples supported thereon, toward theanvil 18.

Further to the above, the sled 32 is moved distally by a firing member25. The firing member 25 is configured to contact the sled 32 and pushthe sled 32 from the proximal position 40 (FIG. 4) adjacent the proximalend 22 toward the distal position adjacent the distal end 23. Thelongitudinal slot 27 defined in the cartridge body 21 is configured toreceive the firing member 25. The anvil 18 also includes a slotconfigured to receive the firing member 25. The firing member 25 furthercomprises a first cam 34 which engages the first jaw 14 and a second cam35 which engages the second jaw 15. As the firing member 25 is advanceddistally, the first cam 34 and the second cam 35 can control thedistance, or tissue gap, between the deck 24 of the staple cartridge 16and the anvil 18. The firing member 25 also comprises a knife 37configured to incise the tissue captured intermediate the staplecartridge 16 and the anvil 18.

The shaft 11 encompasses and guides a firing motion from the housing 19through a longitudinally-reciprocating laminated firing bar 39 extendingproximally from the firing member 25. In particular, the shaft 11includes a longitudinal firing bar slot that receives the firing bar 39.It should be appreciated that the firing bar 39 may be substituted witha solid firing bar or of other materials in applications not intended topass through the articulation joint 20, such as depicted in FIG. 4.

Referring primarily to FIGS. 4 and 5, the surgical instrument 10includes a firing lockout mechanism 45 that is configured to prevent thefiring member 25 from being advanced in the absence of an unfired staplecartridge 16. The firing lockout mechanism 45 can only be bypassed whenthe sled 32 is positioned in a proximal, initial, or unfired position,as illustrated in FIGS. 9-11. The firing lockout mechanism 45 includes alockout pawl 46 rotatable about a pivot 47 which can be secured to theshaft 11. In the example illustrated in FIG. 4, the pivot 47 extendstransversely with respect to a longitudinal axis defined by the firingbar 39. The pivot 47 is suspended in a position proximal to the firingmember 25.

Further to the above, the lockout pawl 46 includes a base 48 and twoarms 49 that extend distally from the base 48 straddling the firingmember 25. Each of the arms 49 includes a cam feature 50 configured tobe received in a corresponding cam slot 51. The cam slots 51 are definedon opposite sides of the firing member 25. In the example of FIG. 4, thebase 48 is rotatable relative to the pivot 47. In other examples,however, the base 48 can be integral with, or attached to, the pivot 47such that the two are rotatable together about an axis transverse to thelongitudinal axis defined by the firing bar 39. Each of the arms 49further includes a locking feature 52 at a distal portion thereof. Thelocking features 52 are bent away from the first cam 34, and toward thesecond cam 35. In certain examples, as illustrated in FIG. 4, thelocking features form a hook shape which permits the locking features 52to stop or block advancement of the firing member 25 by catching lockoutwings 53 of the firing member 25 in receiving portions 69 of the lockingfeatures 52 that are adapted form mating engagement with the lockoutwings 53. In various examples, however, the locking features 52 maycomprise other shapes and/or may be bent in other directions.

Referring primarily to FIGS. 6-8, the firing lockout mechanism 45permits a limited motion of the firing member 25 beyond which, and inthe absence of an unfired staple cartridge 16, the firing member 25 isstopped or blocked by locking features 52 of the lockout pawl 46. FIG. 6illustrates the firing member 25 in a resting or initial position, wherethe locking features 52 are received in corresponding retention pockets54 on opposite sides of the firing member 25, as illustrated in FIG. 4.While in the retention pockets 54, the locking features 52 maintain thefiring member 25 at the resting or initial position by resisting anyinadvertent movement of the firing member 25. The inadvertent movementmay occur due to any slack in the firing mechanism. The retentionpockets 54 ensure that the firing member 25 remains in the resting orinitial position until the firing member 25 is advanced by the firingbar 39.

FIG. 7 illustrates the firing member 25 in a slightly advanced positiondistal to the resting or initial position. The distal advancement of thefiring member 25 by the firing bar 39 causes the locking features 52 tobecome disengaged from the retention pockets 54. In addition, suchdistal advancement of the firing member 25 causes the cam slots 51 todrive the cam features 50 in a predetermined path, which causes thelockout pawl 46 to rotate in a counterclockwise direction about thepivot 47. In the absence of an unfired staple cartridge 16, or in theabsence of a sled positioned in a proximal, initial, or unfiredposition, the rotation of the lockout pawl 46 directs the lockingfeatures 52 into a locking engagement with the lockout wings 53 of thefiring member 25, as illustrated in FIG. 8. In other words, an initialadvancement of the firing member 25 in the absence of an unfired staplecartridge 16, or in the absence of a sled positioned in a proximal,initial, or unfired position, automatically activates the firing lockoutmechanism 45 to block, stop, or at least resist, further advancement ofthe firing member 25.

FIGS. 9-11 depict a sequence of positions of the firing member 25 thatis similar in many respects to the sequence depicted in FIGS. 6-8. Thedifference, however, is in the presence of an unfired staple cartridge16 that is attached to the first jaw 14. FIG. 9 illustrates the firingmember 25 in a resting or initial position, where the locking features52 are received in the corresponding retention pockets 54. In addition,the sled 32 is depicted in a proximal, initial, or unfired position.

FIG. 7 illustrates the firing member 25 in a slightly advanced positiondistal to the resting or initial position. The distal advancement of thefiring member 25 by the firing bar 39 causes the locking features 52 tobecome disengaged from the retention pockets 54. In addition, suchdistal advancement of the firing member 25 causes the cam slots 51 todrive the cam features 50 in a predetermined path, which causes thelockout pawl 46 to rotate in a counterclockwise direction about thepivot 47. The sled 32 includes lockout bypass features 57 which areconfigured to intercept the locking features 52 to prevent the lockingfeatures 52 from engaging the lockout wings 53. In other words, thelockout pawl 46 is configured to rest against the lockout bypassfeatures 57 of the sled 32, which permits further advancement of thefiring member 25 with the sled 32 to complete the firing of the staplecartridge 16, as illustrated in FIG. 11.

FIGS. 12-14 depict a sequence of positions of the firing member 25 thatrepresents retraction of the firing member 25 by the firing bar 39 to aninitial or resting position after completion of the firing of the staplecartridge 16. FIG. 12 illustrates the lockout wings 53 of the firingmember 25 re-engaging the lockout pawl 46. The lockout wings 53 compriseproximal ramp portions 58 that are configured to lift the lockingfeatures 52 as the firing member 25 is retracted toward the initial orresting position. The proximal ramp portions 58 engage flat, or at leastsubstantially flat, portions 59 of outer ribs 60 of the locking features52 causing rotation of the lockout pawl 46 in a clockwise direction.

As illustrated in FIG. 13, as the firing member 25 continues to moveproximally, the locking features 52 clear the lockout wings 53. Inaddition, the cam features 50 are re-engaged by the cam slots 51, whichdrive the cam features 50 to further rotate the lockout pawl 46, in aclockwise direction, about the pivot 47 until the firing member 25reaches the initial or resting position, as illustrated in FIG. 14. Thelocking features 52 are also returned to the retention pockets 54. Anyadditional proximal movement of the firing member 25 causes the firingbar 39 to abut against a hard stop 61 (FIG. 14), which is configured toprevent the firing member 25 from any further proximal movement. In theexample illustrated in FIG. 14, the hard stop 61 is a mechanical featuredefined in the shaft 11 that is configured to interrupt, stop, and/orblock further proximal movement of the firing bar 39, which interrupts,stops, and/or blocks further proximal movement of firing member 25. Incertain examples, however, the hard stop 61 can be configured todirectly engage the firing member 25.

Referring to FIG. 16, in various examples, the movement of the firingbar 39 and, consequently, the firing member 25 is driven by a motor 71operably coupled to the firing bar 39. The motor 71 is controlled by amotor driver 72. FIG. 16 illustrates a logic diagram of a circuit 65configured to detect the return of the firing member 25 to the initialor resting position, and to deactivate the motor 71. The circuit 65includes a controller 66 comprising a processor 67 and a memory 68.

The motor driver 72, based on input from the controller 66, can beconfigured to control the rotation of the motor 71 to advance andretract the firing bar 39 and, consequently, the firing member 25. Oneor more sensors 70 can be configured to detect the presence of thefiring member 25 at the initial or resting position. The controller 66may be configured to receive feedback input from the sensors 70indicative of the presence of the firing member 25 at the initial orresting position. The controller 66 may also be configured to cause themotor driver 72 to stop the motor 71 in response to receiving an inputfrom the sensors 70 indicating that the firing member 25 has beenreturned to the initial or resting position. The memory 68 may store atechnique, an equation, and/or a look-up table which can be employed bythe controller 66 in the assessment.

In at least one example, the return of the firing member 25 to theinitial or resting position can be determined based on input from a loadcell placed onto the hard stop 61 in the path of the firing member 25.As the firing bar 39 abuts against the load cell and the hard stop 61,the load cell detects an increase in force applied by the firing bar 39against the hard stop 61. The controller 66 receives input from the loadcell, which can be compared to a predetermined threshold. The controller66 determines that the firing member 25 has reached the initial orresting position when the input from the load cell is equal to or lessthan the predetermined threshold. In response to such determination, thecontroller 66 stops the motor 71.

Referring to FIG. 15, a sequence 75 of positions 76-79 illustrate theinteraction between the firing member 25 and the lockout pawl 46 duringadvancement of the firing member 25 by the firing bar 39 to fire thestaple cartridge 16. The positions are ordered chronologically from topto bottom. In the first or top position 76, the firing member 25 is inthe initial or resting position and, as described above, the lockingfeatures 52 of the lockout pawl 46 are received in the retention pockets54. In the second position 77, the firing member 25 is slightly advancedistally, which causes the arms 49 of the lockout pawl 46 to flexoutward, away from one another, as the locking features 52 exit theretention pockets 54.

As illustrated in FIG. 5, the cam slots 51 have a shape that is similarto a hockey-stick. The cam slots 51 are defined in the body of thefiring member 25 on opposite sides thereof. Each of the cam slots 51includes a curved portion 51 b with a horizontal, or at leastsubstantially horizontal, proximal portion 51 a extending from one endof the curved portion 51 b, and a slanted distal portion 51 c extendingfrom the other end of the curved portion 51 b. The proximal portion 51 aand the distal portion 51 c define an angle (α) therebetween that isgreater than 90°. In the third position 78, as illustrated in FIG. 15,the cam features 50 snap into the distal portions 51 c of cam slots 51as the arms 49 flex inward toward one another. As the firing member 25transitions from the second position 77 to the third position 78, thearms 49 of the lockout pawl 46 flex to permit the cam features 50 tocross over ribs 80 that extend between the retention pockets 54 and thedistal portions 51 c of the cam slots 51.

As described above, the motion of the cam features 50 relative to thecam slots 51 guides and/or drives the counterclockwise rotation of thelockout pawl 46. As the firing member 25 is advanced distally by thefiring bar 39, in the absence of an unfired staple cartridge 16, the camfeatures 50 are guided toward the curved portion 51 b and, then, towardthe proximal portion 51 a. In addition, in the absence of an unfiredstaple cartridge 16, the cam features 50 are prevented from exiting theproximal portion 51 a because the locking features 52 engage the lockoutwings 53, which prevents the firing member 25 from further distalmovement. Meanwhile, in the presence of an unfired staple cartridge 16,the cam features 50 are guided toward the curved portion 51 b but do notreach the proximal portion 51 a. Instead, the arms 49 of the lockoutpawl 46 flex once more, as indicated the fourth position 79, to permitthe cam features 50 to disengage from the cam slots 51 prior to reachingthe proximal portion 51 a. In the presence of an unfired staplecartridge 16, the lockout bypass features 57 of the sled 32 prevent thelocking features 52 of the lockout pawl 46 from engaging the lockoutwings 53, which permits further advancement of the firing member 25 tocomplete the firing sequence.

Although various devices have been described herein in connection withcertain embodiments, modifications and variations to those embodimentsmay be implemented. Particular features, structures, or characteristicsmay be combined in any suitable manner in one or more embodiments. Thus,the particular features, structures, or characteristics illustrated ordescribed in connection with one embodiment may be combined in whole orin part, with the features, structures or characteristics of one oremore other embodiments without limitation. Also, where materials aredisclosed for certain components, other materials may be used.Furthermore, according to various embodiments, a single component may bereplaced by multiple components, and multiple components may be replacedby a single component, to perform a given function or functions. Theforegoing description and following claims are intended to cover allsuch modification and variations.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, a device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the stepsincluding, but not limited to, the disassembly of the device, followedby cleaning or replacement of particular pieces of the device, andsubsequent reassembly of the device. In particular, a reconditioningfacility and/or surgical team can disassemble a device and, aftercleaning and/or replacing particular parts of the device, the device canbe reassembled for subsequent use. Those skilled in the art willappreciate that reconditioning of a device can utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

The devices disclosed herein may be processed before surgery. First, anew or used instrument may be obtained and, when necessary, cleaned. Theinstrument may then be sterilized. In one sterilization technique, theinstrument is placed in a closed and sealed container, such as a plasticor TYVEK bag. The container and instrument may then be placed in a fieldof radiation that can penetrate the container, such as gamma radiation,x-rays, and/or high-energy electrons. The radiation may kill bacteria onthe instrument and in the container. The sterilized instrument may thenbe stored in the sterile container. The sealed container may keep theinstrument sterile until it is opened in a medical facility. A devicemay also be sterilized using any other technique known in the art,including but not limited to beta radiation, gamma radiation, ethyleneoxide, plasma peroxide, and/or steam.

While this invention has been described as having exemplary designs, thepresent invention may be further modified within the spirit and scope ofthe disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdo not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

EXAMPLES Example 1

A surgical instrument that comprises an end effector, a firing membermovable distally to effect a firing motion in the end effector, and alockout pawl. The firing member comprises a cam slot. The lockout pawlcomprises a cam feature receivable in the cam slot. The cam slot isconfigured to guide the cam feature to cause a rotation of the lockoutpawl between a first position where the lockout pawl permits the distalmovement of the firing member, and a second position where the lockoutpawl prevents the distal movement of the firing member.

Example 2

The surgical instrument of Example 1, wherein the end effector comprisesa sled movable between an unfired position and a fired position.

Example 3

The surgical instrument of Example 2, wherein the sled is configured toprevent the lockout pawl from reaching the second position while thesled is in the unfired position.

Example 4

The surgical instrument of Example 2 or 3, wherein the sled comprises alockout bypass feature extending proximally from the sled, and whereinthe lockout bypass feature is configured to interrupt the rotation ofthe lockout pawl toward the second position while the sled is in theunfired position.

Example 5

The surgical instrument of Example 4, wherein the rotation of lockoutpawl toward the second position is not interrupted by the lockout bypassfeature while the sled is in the fired position.

Example 6

The surgical instrument of Example 1, 2, 3, 4, or 5, wherein the firingmember comprises a lockout member protruding laterally from the firingmember, and wherein the lockout pawl comprises a locking featureconfigured to lockingly engage the lockout member when the lockout pawlis in the second position.

Example 7

The surgical instrument of Example 6, wherein the lockout membercomprises a wing shape.

Example 8

The surgical instrument of Example 6 or 7, wherein the lockout membercomprises a proximal portion and a distal portion greater in size thanthe proximal portion.

Example 9

The surgical instrument of Example 8, wherein the locking featurecomprises a receiving portion adapted for mating engagement with thedistal portion of the lockout member.

Example 10

The surgical instrument of Example 1, 2, 3, 4, 5, 6, 7, 8, or 9, whereinthe cam slot comprises a first slot portion and a second slot portiondefining an obtuse angle with the first slot portion.

Example 11

The surgical instrument of Example 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10,wherein the firing member comprises a cutting member.

Example 12

The surgical instrument of Example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11,wherein the lockout pawl comprises a distal locking feature, and whereinthe firing member comprises a retaining pocket configured to secure thedistal locking feature while the lockout pawl is in the first position.

Example 13

A surgical instrument that comprises a shaft, an end effector extendingdistally from the shaft, a hard stop, a firing assembly, and a lockoutpawl. The end effector comprises a staple cartridge including aplurality of staples. The firing assembly is movable distally from ahome position to deploy the staples from the staple cartridge. Thefiring assembly is configured to abut against the hard stop at the homeposition. The firing assembly comprises a firing member including a camslot. The lockout pawl comprises a cam feature receivable in the camslot. The cam feature is configured to disengage from the cam slotduring the distal movement of the firing assembly. The cam feature isconfigured to reengage the cam slot during return of the firing assemblyto the home position.

Example 14

The surgical instrument of Example 13, wherein the cam slot isconfigured to guide the cam feature to cause a rotation of the lockoutpawl between a first position where the lockout pawl permits the distalmovement of the firing member, and a second position where the lockoutpawl prevents the distal movement of the firing member.

Example 15

The surgical instrument of Example 14, wherein the end effectorcomprises a sled movable by the firing assembly between an unfiredposition and a fired position, and wherein the sled is configured toprevent the lockout pawl from reaching the second position while thesled is in the unfired position.

Example 16

The surgical instrument of Example 15, wherein the sled comprises alockout bypass feature extending proximally from the sled, and whereinthe lockout bypass feature is configured to interrupt the rotation ofthe lockout pawl toward the second position while the sled is in theunfired position.

Example 17

The surgical instrument of Example 13, 14, 15, or 16, further comprisinga sensor configured to detect the abutment of the firing assemblyagainst the hard stop at the home position.

Example 18

A surgical instrument that comprises a shaft, an end effector extendingdistally from the shaft, a firing assembly, and a lockout pawl. The endeffector comprises a staple cartridge including a plurality of staples.The firing assembly is movable distally from a home position to deploythe staples from the staple cartridge. The firing assembly comprises afiring member. The firing member comprises a cam slot and a retentionpocket. The lockout pawl comprises a locking feature receivable in theretention pocket and a cam feature receivable in the cam slot. The camfeature is configured to disengage from the cam slot during the distalmovement of the firing assembly. The cam feature is configured toreengage the cam slot during return of the firing assembly to the homeposition. The cam slot is configured to guide the locking feature intothe retention pocket during the return of the firing assembly to thehome position.

Example 19

The surgical instrument of Example 18, wherein the firing membercomprises a lockout wing, wherein the lockout pawl comprises a lockingfeature, and wherein the lockout wing is configured to lift the lockingfeature during the return of the firing assembly to the home position tocause the cam feature to reengage the cam slot.

1-19. (canceled)
 20. A surgical instrument, comprising: an end effector;a firing member movable distally from a home position to effect a firstfiring motion in the end effector, wherein the firing member is movableproximally toward the home position in a return motion, and wherein thefiring member comprises a cam slot; and a lockout pawl comprising a camfeature receivable in the cam slot during the return motion, wherein thecam slot is configured to guide the cam feature and move the lockoutpawl toward a locking engagement with the firing member to prevent asecond firing motion of the firing member.
 21. The surgical instrumentof claim 20, wherein the end effector comprises a sled movable toward afired position during the first firing motion.
 22. The surgicalinstrument of claim 21, wherein an absence of the sled during the returnmotion allows the lockout pawl to reach the locking engagement with thefiring member.
 23. The surgical instrument of claim 22, wherein the sledcomprises a lockout bypass feature extending proximally from the sled,and wherein the lockout bypass feature is configured to interrupt therotation of the lockout pawl toward the locking engagement with thefiring member.
 24. The surgical instrument of claim 23, wherein therotation of lockout pawl is not interrupted by the lockout bypassfeature while the sled is in the fired position.
 25. The surgicalinstrument of claim 24, wherein the firing member comprises a lockoutmember protruding laterally from the firing member, and wherein thelockout pawl comprises a locking feature configured to lockingly engagethe lockout member terminating the return motion of the firing member.26. The surgical instrument of claim 25, wherein the lockout membercomprises a wing shape.
 27. The surgical instrument of claim 25, whereinthe lockout member comprises a proximal portion and a distal portion,wherein the distal portion is greater in size than the proximal portion.28. The surgical instrument of claim 27, wherein the locking featurecomprises a receiving portion adapted for mating engagement with thedistal portion of the lockout member.
 29. The surgical instrument ofclaim 20, wherein the cam slot comprises a first slot portion and asecond slot portion defining an obtuse angle with the first slotportion.
 30. The surgical instrument of claim 20, wherein the firingmember comprises a cutting member.
 31. The surgical instrument of claim20, wherein the lockout pawl comprises a distal locking feature, andwherein the firing member comprises a retaining pocket configured tosecure the distal locking feature while the lockout pawl is in thelocking engagement with the firing member.
 32. A surgical instrument,comprising: a shaft; an end effector extending distally from the shaft,wherein the end effector comprises a staple cartridge including aplurality of staples; a hard stop; a firing assembly movable distallyfrom a home position to deploy the staples from the staple cartridge,wherein the firing assembly is configured to abut against the hard stopat the home position, wherein the firing member is movable proximallytoward the home position in a return motion, and wherein the firingassembly comprises a firing member including a cam slot; and a lockoutpawl comprising a cam feature receivable in the cam slot, wherein thecam feature is configured to disengage from the cam slot during thedistal movement of the firing assembly, wherein the cam feature isconfigured to reengage the cam slot during a return motion of the firingassembly to the home position, causing the lockout pawl to move toward alocking engagement with the firing member to prevent a second firingmotion of the firing member.
 33. The surgical instrument of claim 32,wherein the end effector comprises a sled movable by the firing assemblytoward a first position during the first firing motion.
 34. The surgicalinstrument of claim 33, wherein an absence of the sled during the returnmotion allows the lockout pawl to reach the locking engagement with thefiring member.
 35. The surgical instrument of claim 34, furthercomprising a sensor configured to detect an abutment of the firingassembly against the hard stop at the home position.
 36. A surgicalinstrument, comprising: a shaft; an end effector extending distally fromthe shaft, wherein the end effector comprises a staple cartridgeincluding a plurality of staples; a firing assembly movable distallyfrom a home position to deploy the staples from the staple cartridge,wherein the firing assembly comprises a firing member, and wherein thefiring member comprises: a cam slot; and a retention pocket; and alockout pawl, comprising: a locking feature receivable in the retentionpocket; and a cam feature receivable in the cam slot, wherein the camfeature is configured to engage the cam slot during return of the firingassembly to the home position, and wherein the cam slot is configured toguide the locking feature into the retention pocket during the return ofthe firing assembly to the home position.
 37. The surgical instrument ofclaim 36, wherein the firing member comprises a lockout wing, andwherein the lockout wing is configured to lift the locking featureduring the return of the firing assembly to the home position to causethe cam feature to reengage the cam slot.
 38. The surgical instrument ofclaim 36, further comprising a sensor configured to detect the return ofthe firing assembly to the home position.